Manganese dioxide

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not conducted to GLP but follows basic scientific principles.

Data source

Reference

Reference Type:

publication

Title:

Particles and SO2 - Synergistic effects for pulmonary damage

Author:

Rylander R and Bergström R

Year:

1973

Bibliographic source:

Proceedings of the 3rd International Clean Air Congress, PA23-A25

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The effect of MnO2 on the respiratory tract was investigated by exposing guinea pigs for 28 days.

GLP compliance:

no

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): manganese dioxide

Test animals

Species:

guinea pig

Strain:

other: conventional and infection controlled animals were used

Sex:

not specified

Details on test animals and environmental conditions:

TEST ANIMALS
- Diet: ad libitum
- Water: tap water

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Remarks on MMAD:

MMAD / GSD: > 0.5 µm < 5.0 µm

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- System of generating particulates/aerosols: MnO2 dust was generated in a Rag Pe aerosol generator.
- Air change rate: 4 air changes per hour.
- Method of particle size determination: Royco Model 225 particle counter was used. At 20mg MnO2/m³ approx 600 000 particles per minute were found to be >0.5µm and <5.0µm in diameter.

Duration of treatment / exposure:

28 days

Frequency of treatment:

No data

Doses / concentrations

Remarks:

Doses / Concentrations:
20 mg/m3
Basis:

No. of animals per sex per dose:

No data

Control animals:

yes

Results and discussion

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Exposure to MnO2 caused a slight increase in the number of macrophages in the infection controlled group. The number of leukocytes was increased in both types of Guinea-pig. MnO2 caused a slight increase in the irritation score when compared to controls. This was more apparent in infection controlled animals.

Applicant's summary and conclusion

Conclusions:

Effects of MnO2 on the infection controlled group were not observed in the normal animals.